A semiconductor light emitting device, such as a light emitting diode (LED), is a device which emits light when electrical energy is applied thereto. In the semiconductor light emitting device, energy is generated when electrons and holes are combined at junctions between semiconductor layers, and the energy is converted to light such that the light is emitted. The light emitting diode is widely used in lighting devices, display devices, and illumination devices, and has been rapidly developed.
In particular, as the development and the use of light emitting diodes (e.g. gallium nitride semiconductors) has expanded in areas of, for example, cell phone keypads, vehicle lamps, camera flashes, and the like, lighting devices using the light emitting diodes have been actively developed. As light emitting diodes that are used as light sources in devices such as automobile headlights and backlight units of big-screen televisions (TVs) have an increased size, as well as being increased in both capacity and efficiency, there is an increasing need for a high-quality light emitting diode with improved characteristics.
As light emitting diodes are widely used, the use of light emitting device modules having a plurality of light emitting diodes disposed therein to increase the amount of light emitted therefrom has increased. However, when a stable supply of electricity is not provided, a light emitting diode may be damaged due to an unstable power supply. In this case, a light emitting device module having a plurality of light emitting diodes therein may be entirely damaged. Thus, a method of preventing light emitting device modules from being damaged is needed.